<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
<style>
    .box{
        width: 300px;
        height: 120px;
        border: 1px solid black;
        margin: 10px auto;
        display: flex;
        flex-wrap: wrap;
    } 
    .box div{
        width: 60px;
        height: 60px;
        background: red;
        border: 1px dashed yellow;
        box-sizing: border-box;
    }
</style>
</head>
<body>
    <div class="box">
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
    </div>
</body>
</html>